Molecular mapping of resistance to Leptosphaeria maculans in Australian cultivars of Brassica napus

Genome ◽  
1997 ◽  
Vol 40 (3) ◽  
pp. 294-301 ◽  
Author(s):  
R. Mayerhofer ◽  
A. G. Good ◽  
V. K. Bansal ◽  
M. R. Thiagarajah ◽  
G. R. Stringam
Keyword(s):  
Brassica Napus ◽  
Molecular Mapping ◽  
Bulked Segregant Analysis ◽  
Leptosphaeria Maculans ◽  
Rflp Markers ◽  
Dh Population ◽  
Dna Mapping ◽  
Resistant Varieties ◽  
Dh Lines ◽  
Blackleg Fungus

Doubled haploid (DH) lines together with a cotyledon bioassay were employed for the molecular analysis of resistance to the blackleg fungus Leptosphaeria maculans in the Australian Brassica napus cultivars Shiralee and Maluka. We used bulked segregant analysis to identify 13 RAPD and two RFLP markers linked to the resistance phenotype and mapped these markers in the segregating DH population. Our data suggest the presence of a single major locus controlling resistance in the cultivar Shiralee, confirming our previous results obtained from Mendelian genetic analyses. In addition, preliminary mapping data for the cultivar Maluka also support a single locus model for resistance and indicate that the resistance genes from 'Shiralee' and 'Maluka' are either linked or possibly identical. The molecular markers identified in this study should be a useful tool for breeding blackleg resistant varieties using marker-assisted selection, and are the essential first step towards the map-based cloning of this resistance gene.Key words: blackleg, Leptosphaeria maculans, Brassica napus, DNA mapping, disease resistance.

The identification of restriction fragment length polymorphisms linked to seed colour genes in Brassica napus

Genome ◽  
1995 ◽  
Vol 38 (3) ◽  
pp. 534-542 ◽  
Author(s):  
A. E. Van Deynze ◽  
B. S. Landry ◽  
K. P. Pauls
Keyword(s):  
Brassica Napus ◽  
Restriction Fragment ◽  
Fragment Length ◽  
Restriction Fragment Length Polymorphisms ◽  
Rflp Markers ◽  
Seed Colour ◽  
Dh Population ◽  
Length Polymorphisms ◽  
Dh Lines ◽  
Restriction Fragment Length

Restriction fragment length polymorphisms (RFLPs) linked to genes controlling seed colour were identified in rapeseed (Brassica napus). The efficiency of the RFLP analysis was enhanced by utilizing bulked segregant analysis, DNA clones that had previously been used to construct a RFLP map of B. napus, and a doubled-haploid (DH) population segregating for seed colour. Markers for two of the three seed colour genes segregating in the DH population were identified on the basis of χ2 analyses of marker distributions among visually classified black-, brown-, and yellow-seeded DH lines as well as ANOVA and quantitative trait locus analysis of light-reflectance measurements from seeds of the DH lines. The RFLP markers linked to seed colour that were identified in the present study will allow breeding strategies based on genotype selection to be developed for seed colour in rapeseed.Key words: RFLP markers, seed colour genes, rapeseed.

Molecular mapping of a thermosensitive genetic male sterility gene in rice using bulked segregant analysis

Genome ◽  
1997 ◽  
Vol 40 (2) ◽  
pp. 188-194 ◽  
Author(s):  
P. K. Subudhi ◽  
R. P. Borkakati ◽  
S. S. Virmani ◽  
N. Huang
Keyword(s):  
Male Sterility ◽  
Molecular Mapping ◽  
Bulked Segregant Analysis ◽  
Pcr Primers ◽  
Rflp Markers ◽  
Arbitrary Primers ◽  
Repulsion Phase ◽  
Genetic Male Sterility ◽  
True Breeding ◽  
Efficient Alternative

The thermosensitive genetic male sterility (TGMS) system is considered to be a more efficient alternative to the cytoplasmic male sterility (CMS) system for hybrid rice. An F2 population from a cross between a TGMS mutant line (IR32364TGMS) and IR68 was used to map the TGMS gene tms3(t). Fertile and sterile bulks were constructed following the classification of F2 plants into true breeding sterile, fertile, and segregating fertile plants based on F3 family studies. From the survey of 389 arbitrary primers in bulked segregant analysis, four RAPD markers were identified in which three, OPF182600, OPB19750, and OPAA7550, were linked to tms3(t) in repulsion phase and one, OPAC3640, was linked to tms3(t) in coupling phase. The tms3(t) gene was flanked by OPF182600 and OPAC3640 on one side and by OPAA7550 and OPB19750 on the other side. All four markers were low-copy sequences and two of them (OPF182600 and OPAC3640) detected polymorphism when the markers were used to probe the genomic blots. Subsequently, OPAC3640 was mapped to the short arm of chromosome 6 using a mapping population available at IRRI. However, no RFLP markers from this region showed linkage to tms3(t) owing to the lack of polymorphism between the parents. All RAPD fragments were cloned and partially sequenced from both ends. Thus, PCR primers can be designed to develop PCR markers for marker-assisted breeding to facilitate the transfer of tms3(t) from one genetic background to another.Key words: bulked segregant analysis, gene tagging, marker-assisted selection, RAPD, TGMS.

Variation in the responses of rapeseed (Brassica napus and B. campestris) cultivars to blackleg (Leptosphaeria maculans) infection

1977 ◽  
Vol 17 (86) ◽  
pp. 445 ◽  
Author(s):  
N Thurling ◽  
LA Venn
Keyword(s):  
Brassica Napus ◽  
Significant Variation ◽  
Brassica Campestris ◽  
Leptosphaeria Maculans ◽  
The Other ◽  
Controlled Environment ◽  
Disease Development ◽  
Fungal Populations ◽  
Different Populations ◽  
Blackleg Fungus

The responses of 53 cultivars of the rapeseed species Brassica napus and Brassica campestris to infection by three different populations of the blackleg fungus, Leptosphaeria maculans, were examined in a controlled environment. Significant variation in disease development was observed between cultivars as well as between fungal populations which had been derived from diseased stubble collected at widely separated sites in Western Australia. A large proportion of the cultivars tested were either susceptible or only slightly resistant to infection by each of the three fungal populations whereas only one cultivar, Zollerngold, was highly resistant to all fungal populations. Several other cultivars, however, were resistant to one population and susceptible or slightly resistant to the other two. In these cases, marked interactions between host and parasite were evident, some cultivars being substantially more resistant than others to infection by spores from a particular population.

Genetics and molecular mapping of resistance to Plasmodiophora brassicae pathotypes 2, 3, 5, 6, and 8 in rutabaga (Brassica napus var. napobrassica)

Genome ◽  
2016 ◽  
Vol 59 (10) ◽  
pp. 805-815 ◽  
Author(s):  
Muhammad Jakir Hasan ◽  
Habibur Rahman
Keyword(s):  
Brassica Napus ◽  
Doubled Haploid ◽  
Genetic Basis ◽  
Molecular Mapping ◽  
Plasmodiophora Brassicae ◽  
Single Gene ◽  
Genomic Region ◽  
Clubroot Disease ◽  
Dh Population ◽  
Brassica Crops

Clubroot disease, caused by Plasmodiophora brassicae, is a threat to the production of Brassica crops including oilseed B. napus. In Canada, several pathotypes of this pathogen, such as pathotypes 2, 3, 5, 6, and 8, were identified, and resistance to these pathotypes was found in a rutabaga (B. napus var. napobrassica) genotype. In this paper, we report the genetic basis and molecular mapping of this resistance by use of F2, backcross (BC1), and doubled haploid (DH) populations generated from crossing of this rutabaga line to a susceptible spring B. napus canola line. The F1, F2, and BC1 populations were evaluated for resistance to pathotype 3, and the DH population was evaluated for resistance to pathotypes 2, 3, 5, 6, and 8. A 3:1 segregation in F2 and a 1:1 segregation in BC1 were found for resistance to pathotype 3, and a 1:1 segregation was found in the DH population for resistance to all pathotypes. Molecular mapping by using the DH population identified a genomic region on chromosome A8 carrying resistance to all five pathotypes. This suggests that a single gene or a cluster of genes, located in this genomic region, is involved in the control of resistance to these pathotypes.

Molecular mapping and validation of Rlm1 gene for resistance to Leptosphaeria maculans in canola (Brassica napus L.)

2012 ◽  
Vol 63 (10) ◽  
pp. 1007 ◽  
Author(s):  
Rosy Raman ◽  
Belinda Taylor ◽  
Kurt Lindbeck ◽  
Neil Coombes ◽  
Denise Barbulescu ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Ssr Markers ◽  
Genomic Sequence ◽  
Molecular Mapping ◽  
Durable Resistance ◽  
Leptosphaeria Maculans ◽  
Doubled Haploid Population ◽  
Brassica Napus L ◽  
Breeding Populations ◽  
Independent Population

European winter canola (Brassica napus L.) cultivars harbour genes for durable resistance to the fungus Leptosphaeria maculans, which causes blackleg disease under Australian environmental conditions. Previous studies have shown that resistance in winter-type cultivars Maxol and Columbus is controlled by two genes, Rlm1 and Rlm3, which have been mapped using randomly amplified polymorphic DNA markers onto chromosome A7. We mapped a doubled-haploid population that consisted of 101 lines from a cross between Maxol*1 and Westar-10 using diversity arrays technology and simple sequence repeat (SSR)-based markers. Two SSR marker loci, Xol12-e03 and Xra2-a05b, flanked the Rlm1 locus at an interval of 6.7 cM, which corresponds to ~3.2 Mb of the Brassica rapa genomic sequence; this region contains several genes encoding putative kinase and leucine-rich repeat-type disease-resistance proteins. SSR markers were further tested for their linkage with the Rlm1 locus in an independent population derived from Columbus*3/Westar-10. Our results showed that SSR markers linked to Rlm1 can be useful for monitoring Rlm1 gene introgression in breeding populations derived from Maxol and Columbus.

Introgression of B-genome chromosomes in a doubled haploid population of Brassica napus × B. carinata

Genome ◽  
2010 ◽  
Vol 53 (8) ◽  
pp. 619-629 ◽  
Author(s):  
Z. K. Navabi ◽  
I. A.P. Parkin ◽  
J. C. Pires ◽  
Z. Xiong ◽  
M. R. Thiagarajah ◽  
...  
Keyword(s):  
Doubled Haploid ◽  
Seed Quality ◽  
Agronomic Traits ◽  
Interspecific Cross ◽  
Leptosphaeria Maculans ◽  
Erucic Acid Content ◽  
Doubled Haploid Population ◽  
Dh Population ◽  
B Genome ◽  
Dh Lines

The Brassica B-genome species possess many valuable agronomic and disease resistance traits. To transfer traits from the B genome of B. carinata into B. napus , an interspecific cross between B. napus and B. carinata was performed and a doubled haploid (DH) population was generated from the BC2S3 generation. Successful production of interspecific DH lines as identified using B-genome microsatellite markers is reported. Five percent of DH lines carry either intact B-genome chromosomes or chromosomes that have deletions. All of the DH lines have linkage group J13/B7 in common. This was further confirmed using B. nigra genomic DNA in a fluorescent in situ hybridization assay where the B-genome chromosomes were visualized and distinguished from the A- and C-genome chromosomes. The 60 DH lines were also evaluated for morphological traits in the field for two seasons and were tested for resistance to blackleg, caused by Leptosphaeria maculans , under greenhouse conditions. Variation in the DH population followed a normal distribution for several agronomic traits and response to blackleg. The lines with B-genome chromosomes were significantly different (p < 0.01) from the lines without B-genome chromosomes for both morphological and seed quality traits such as days to flowering, days to maturity, and erucic acid content.

Alloplasmic male sterile Brassica napus with Enarthrocarpus lyratus cytoplasm: introgression and molecular mapping of an E. lyratus chromosome segment carrying a fertility restoring gene

Genome ◽  
2003 ◽  
Vol 46 (5) ◽  
pp. 792-797 ◽  
Author(s):  
H S Janeja ◽  
S K Banga ◽  
P B Bhaskar ◽  
S S Banga
Keyword(s):  
Brassica Napus ◽  
Cytoplasmic Male Sterility ◽  
Male Sterility ◽  
Molecular Mapping ◽  
Bulked Segregant Analysis ◽  
Fertility Restoration ◽  
Hybrid Seed Production ◽  
Male Sterile ◽  
Fertility Restorer ◽  
Donor Species

A cytoplasmic male sterility (CMS) system for Brassica napus (2n = 38; AACC) was developed by backcross substitution of its nucleus into the cytoplasm of a wild crucifer, Enarthrocarpus lyratus. Male sterility was complete, stable, and expressed in small flowers with rudimentary anthers. Since the B. napus germplasm lines were complete or partial maintainers of male sterility, the required fertility restorer gene (Rfl) was introgressed from the cytoplasm donor species. Inheritance studies carried out on F1 and F2 populations derived from hybridizing cytoplasmic male sterile and male fertile near-isogenic (PNILs) lines of B. napus 'Westar', revealed a monogenic dominant control for fertility restoration. Bulked segregant analysis with 215 RAPD primers helped in the identification of putative primers associated with fertility restoration. Co-segregation analysis of eight such primers with Rfl gene revealed two markers, OPK 15700 and OPZ 061300, which flank the Rfl locus on either side at a distance of 8.2 and 2.5 cM, respectively. These DNA markers will be useful in marker-assisted selection for improving the commercial potential of this newly developed CMS-fertility-restorer system for hybrid seed production programs in rapeseed.Key words: oilseed rape, hybrids, cytoplasmic male sterility, fertility restoration, RAPD mapping.

Non-aggressive Strains of the Blackleg Fungus, Leptosphaeria maculans, Are Present in Australia and Can Be Distinguished From Aggressive Strains by Molecular Analysis

1994 ◽  
Vol 42 (1) ◽  
pp. 1 ◽  
Author(s):  
KM Plummer ◽  
K Dunse ◽  
BJ Howlett
Keyword(s):  
Brassica Napus ◽  
North America ◽  
Molecular Analysis ◽  
Ribosomal Rna ◽  
Random Amplified Polymorphic Dna ◽  
Rapd Marker ◽  
Leptosphaeria Maculans ◽  
Morphological Characters ◽  
Molecular Techniques ◽  
Blackleg Fungus

Isolates of the pathogenic ascomycete Leptosphaeria maculans have been cultured from blackleg-affected oilseed rape (Brassica napus) stubble from Horsham, Victoria. These isolates are indistinguishable on the basis of morphological characters, but can be classified as either aggressive or non-aggressive by their ability to infect B. napus cultivars Midas and Westar. These aggressive and non-aggressive isolates of L. maculans can be distinguished by molecular techniques including electrophoretic karyotyping, Southern analysis of the ribosomal RNA gene repeat, Random Amplified Polymorphic DNA (RAPD) marker analysis, and pigment production. The presence of aggressive and non-aggressive strains of L. maculans in North America and Europe has been previously described. This is the first report of non-aggressive L. maculans strains isolated from B. napus in Australia.

Molecular-mapping analysis in Brassica napus using isozyme, RAPD and RFLP markers on a doubled-haploid progeny

1996 ◽  
Vol 93 (7) ◽  
pp. 1017-1025 ◽  
Author(s):  
N. Foisset ◽  
R. Delourme ◽  
P. Barret ◽  
N. Hubert ◽  
B. S. Landry ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Doubled Haploid ◽  
Molecular Mapping ◽  
Rflp Markers ◽  
Mapping Analysis
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